The contest, played out in the main hall before a capacity audience of pupils, was organised by MHSG's Amnesty International group and raised £430.
With Miss Welsby playing the part of Jeremy Paxman, the battle of wits ended in a victory for The University of Life over The Exterminators, 230 points to 70.
Junior Sixth Form student Susannah Thom explained: "It was both an enjoyable and well-supported event that was preceded by a dance performance by three Year 8 pupils, all of whom were inspired by the work of Amnesty International.
"The money we have raised will go towards funding campaigns to highlight human rights abuses across the world," she added.